PBL 7 Flashcards
define pulses alternans
this is a physical finding with arterial pulse waveform showing alternating strong and weak beats, almost always indicative of left ventricular systolic impairment and carries a poor prognosis, there is one weak beat and one strong beat, can occur in hypertension, aortic stenosis, coronary atherosclerosis and dilated cardiomyopathy
define hepatojugular reflux
this is distension of the jugular vein induced when applying manual pressure over the liver, patients torso should be at 45 degree angle, can be seen in TR, cardioic tamponade, right heart side failure
how does heart failure happen
- Systolic heart failure – so the heart cannot pump hard enough
- Diastolic heart failure – reduced preload to the heart
why is congestive heart failure called congestive heart failure
fluid backs up into the lung and can cause fluid overload this is why it is also called congestive heart failure
how does systolic heart failure happen
- Heart needs to give out the CO per minute
- CO = bpm x stroke volume
- LV 70ml in stroke volume
- Can cause a reduce in CO
- Anything less than 40ml or less is considered HF
- Have decreased stroke volume and increased residual volume
how does diastolic heart failure happen
- Stroke volume is low but ejection fraction is normal, this is because although it is not filling enough it is pumping out what is normal in terms of a fraction
- Due to reduced preload
describe the starling mechanism
- Increased preload causes increase force of contraction
- Cardiac muscle can fail when it gets to a certain point
what are cardiac causes of heart failure
- Bicuspid aortic valve
- Valvular heart disease
- Ischemic heart disease
- Hypertension
what are non cardiac causes of heart failure
- Infection
- Overactive thyroid
- Anaemia
- Renal failure
- Medication and drugs
how would diagnose heart failure
- Echocardiogram – pictures of the heart using an ultrasound probe
- ECG
- Stress test
- Blood tests
- Chest x ray
- CT
- Coronary angiogram
- Biopsy
explain her signs and symptoms
- Tiredness – left ventricle cannot pump enough blood when higher O2 is required on exertion thus she exhibits tiredness,
- Shortness of breath especially at night – reduced gas exchange from the alveoli to the blood, this is increased when laying down due to an increase in PVS, the respiratory drive being reduced when sleeping, less sympathetic bronchodilation
- Swollen ankles which are worse in the evenings
- Wakes up after a couple’s hour sleep – pulmonary oedema and hypoxia is more sever that they trigger waking up
- Sleeps with several pillows
- 160/95 hypertension
- 122 bpm tachycardia – compensation by the sympathetic nervous system in order to increase the stroke volume that has been reduced
- Pulsus alternas – shows left systolic impairment, they could have aortic stenosis which has lead to the left sided heart failure
- Systolic mumrus in her chest – either aortic stenosis or mitral regurigitation
- Crackles in the base of both her lungs – this is due to pulmonary oedema, this is caused by blood entering from the pulmonary arteries into the intersitial tissues resulting in fluid build up in her alveoli
- Ankles are slightly swollen – right heart side failure, the fluid is going back from the heart into the body, reduced stroke volume, leads to rasied central venous pressure, starlings law has failed, worse in the evenings due to gravity
- Hepatojugular reflux – sing of raise central venous pressure and right heart side failure
She has both left and right sided heart failure, began in the left and was passed on to the right
what are the key features of left sided heart failure
increased end systolic volume, increased left atrial pressure, increased pulmonary venous
what are the key features for right sided heart failure
Right heart failure = PO and hypoxia cause raised central venous pressure because of increased raised pulmonary arterial pressure and pulmonary arterial constriction (causes right ventricle enlarges).
describe what Non-dihydropyridine calcium channel blockers do
verparmil
dilitizem
Selective for calcium channels in the myocardium in order to decrease heart rate and decrease force of contraction in order to decrease oxygen demand
describe what dihydropyriidine calcium channel blockers do and what are the side effects
amlodipine and nifedipine
Selective for calcium channels in the vessels in order to cause vasodilation and decrease the TPR
other drugs can cause reflexive tachycardia and hypotension and syncope
describe nitrates
- examples
- mechanism of action
- side effects
GTN, Isosoribide (longer acting)
NO causes cGMP rise in smooth muscle which activates myosin light chain phosphatase via cGMP dependent protein kinase thus causes vasodilation ( it causes the dephosphorylation of myosin light chain kinase)
Headache, flushing, tachy/bradycardia
Tolerance to isosorbide can develop
Sublingual or spray is very fast acting
describe nicroandil
- mechanism of action
- side effects
Acts as a nitrate and also opens potassium channels which hyperpolarises the cell and prevents opening of voltage gated calcium channels so net effect is vasodilation.
Flushing, palpitation, GI ulceration
Useful for nitrate tolerance
describe beta blockers
- examples
- mechanism of action
- side effects
Atenolol (selective B2 antaogonsit)
Propanolol (non-selective beta antagonist)
Binds to B2 receptors in the heart decreasing the heart rate and force of contractility, this can increase the end-diastolic volume
Propranolol should not be given for patients who have asthma as it can cause bronchoconstriction
Lethargy
May cause type 2 diabetes
describe ACE/ARB
- mechanism of action
- side effects
Prevents angiotensin I being converted to angiotensin II by blocking the ACE, this prevents angiotensin II binding to an AT1 receptor on smooth muscle and prevents calcium entry which can cause vasodilation
ACE – cough, angioedema, shouldn’t be given to patients of an afrocarbbeian background
ARB is better in this instant
describe diuretics such as furosemide
- mechanism of action
Remove the amount of fluid present in the heart reduce preload therefore reduce the contractile force and oxygen demand of the heart
what are the surgical treatments available
- CABG
- Valve replacement
- Ventricular restoration
- ICD
- Heart transplant
what are the non surgical and non pharmacological treatments available
- Cardiac rehab
- Weight loss
- Sodium fluid restriction
- Oxygen
what are the risks of hear failure
- Diabetes
- Smoking
- Obesity
- Family history
- Air pollution
- Hypertension
- Cholesterol
- Age
what would a chest x ray look like
- Heart should be enlarged – cardiomegaly
- Kurly B lines – interstitial oedema
- Pulmonary oedema
- Upper lobe diversion
- Pleural effusion – blunted costophrenic lines
